University of Groningen The significance of preoperative ... · standard, the Digital Subtraction...
Transcript of University of Groningen The significance of preoperative ... · standard, the Digital Subtraction...
University of Groningen
The significance of preoperative vascular mapping of donor- and acceptor vessels in free flapsurgeryKlein, Steven
IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.
Document VersionPublisher's PDF, also known as Version of record
Publication date:2013
Link to publication in University of Groningen/UMCG research database
Citation for published version (APA):Klein, S. (2013). The significance of preoperative vascular mapping of donor- and acceptor vessels in freeflap surgery. [s.n.].
CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).
Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.
Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.
Download date: 27-03-2021
113
Chapter 9
Summary and general discussion
114
115
Summary and general discussion
Summary
Trauma, oncological resections and pressure sores can lead to major soft tissue defects, which can
create a challenge for surgical closure. Reconstructive surgery has seen great development since the
early 1960s, when the concept of axial vessels became mainstay. In the past 20 years, enormous
progress has been made in flap design and more and more flaps are based on perforating vessels that
branch off and are traced back to well-known vessels, thereby limiting donor-site morbidity. The exact
location of perforators, however, varies significantly, and preoperative vascular mapping has been
introduced to help identify the dominant perforator and its course and, as such, speed up flap harvest.
The aim of this thesis was to investigate the need for and compare various techniques for preoperative
vascular assessment in free flap reconstruction.
In chapter two the evolution of the reconstructive flap surgery is described. This evolution followed the
increased understanding of the vascular anatomy of the skin and subcutis. While the first local flaps for
reconstruction were based on a random vascular pattern, the next generation of flaps was based on an
axial vascular supply. In the Western world, surgeons such as Esser and Machot were the pioneers in
this field around the turn for the nineteenth century. (1,2) Due to the influence of surgeons, like Gillies,
the principle of axial pattern flaps was not expanded until their reinvention in 1969 by Stuart Milton. The
first axial pattern flaps were based on well-known vessels from the anatomy book, such as the radial
artery for the radial forearm flap and the thoracodorsal vessels for the latissimus dorsi flap. The harvest
of these flaps, although in that time revolutionary, is nowadays looked upon as relatively straightforward,
due to their predictable anatomy. In the recent years, more and more flaps have been described that
are based on a single perforating vessel. By the use of such perforator flaps, proper blood supply to the
flap can be combined with less morbidity at the donor site.(3)
In chapter three the “condito sine qua non” of a good vascular supply to a free flap and the donor site is
illustrated with the example of the complicated case histories of three patients in whom a free fibular flap
was harvested. The free fibula flap is the microsurgeon’s workhorse for the reconstruction of osseous or
osteocutaneous defects. Donor-site morbidity of this flap is reported to occur infrequently, and is
generally considered minor and transient. Anatomical variations of vascular patterns, prior vascular
trauma or atherosclerosis can however jeopardize the survival of the free flap and the preservation of
the tissues surrounding the donor site. The drama of flap failure and the occurrence of severe
complications at the donor site stress the importance of decent vascular assessment as part of the
preoperative work-up.
In order to validate a technique and the results of several studies, the method of measurement ought to
be standardized. However this is not always the case, as is presented in the general review in chapter
four about the example of the measurement and calculation of the ankle-arm index (AAI). Since its
introduction in 1950, a variety of methods of measurement and calculation have been used. This has
resulted in variations of its normal range and difficulty in comparing study results. Hence, the objective
of the study depicted in this chapter was to analyze the various methods used to assess AAI and its
116
normal range and to construct a standardized method to assess AAI based on that analysis. This study
resulted in an inventory of the disparate AAI methods and its normal range reported in 100 randomly
selected publications and a recommendation for standardization. We concluded, that the left arm
pressure ought to be used as denominator and the mean of pressures of both tibial arteries of each leg
ought to be used for the numerator of the AAI for that leg. We advocate 0.90 as the cut-off value to
distinguish patients who need further arterial assessment.
The fifth chapter gives an overview of the various methods for vascular mapping of flaps together with
their advantages and disadvantages. The pro’s and con’s of the hand-held Doppler, colour duplex,
digital subtraction angiography (DSA), computed tomographic angiography (CTA) and magnetic
resonance angiography (MRA) are reviewed and discussed. As CTA and MRA are able to produce
detailed 3D images of the vasculature and its surrounding structures, these methods currently are
thought to be the best methods available for mapping the vasculature of donor sites of perforator flaps
with variable anatomy such the upper thigh, the donor site of the Anterolateral Thigh flap (ALT), and the
lower abdomen, donor site of the Deep Inferior Epigastric Perforator (DIEP). In flaps with standard
anatomy and superficial vasculature hand held Doppler remains the method of choice.
In chapter six the ankle-arm index (AAI) is compared to the current golden standard, the Digital
Subtraction Angiography (DSA) for the assessment of the donor site of the fibula free flap. As peripheral
arterial occlusive disease or congenital anomalies of the major crural arteries may limit the use of the
fibula free flap, these conditions should be detected preoperatively. Since DSA has drawbacks, a safer,
cheaper, more accurate and noninvasive alternative is desirable. We tested the hypothesis that AAI of
each of the three crural arteries, combined with pencil Doppler examination of the peroneal skin
perforators, would provide adequate information to restrict the use of angiography to cases in which the
outcomes of either or both of these options are insufficient. The ankle-arm index data of each of the
three crural arteries, as well as pencil Doppler examination of the peroneal skin perforators of both legs
of nine prospectively included patients and the nonoperated legs of 13 retrospectively included patients,
were compared statistically in four different ways with the preoperative angiographic findings. The
conclusion that could be drawn was that combined ankle-arm index and pencil Doppler examination is
not accurate enough to detect legs or arteries with subclinical peripheral arterial occlusive disease or
vascular variation and, hence, is not a sufficient basis on which to develop the surgical plan for a fibula
free flap.
In Chapter seven 3D-TOF Magnetic Resonance Angiography (MRA) is compared to the current golden
standard, the Digital Subtraction Angiography (DSA) for the vascular assessment of the fibula free flap
donor site. Fifteen consecutive patients, scheduled for free vascularized fibular flap transfer, were
subjected to DSA as well as MRA of the crural arteries of both legs (n=30). Two radiologists randomly,
blindly and independently assessed all DSA and MRA images. Each of the assessors scored the
degree of stenosis or hypoplasia of various segments on a 5-point scale from 0 (occlusive) to 4 (no
stenosis). In addition, the number of cutaneous perforators was scored and the assessors were asked if
they would advise against fibula harvest and transplantation based on the images. Substantial
agreement of stenosis severity scores was found between the two imaging techniques. The sensitivity
117
of MRA to detect a stenosis compared to DSA was 0.79, and a specificity of 0.98. In 53 out of 60
assessments, advice on suitability for transfer was equal between DSA and MRA. And the median
number of cutaneous perforators per leg was one for DSA as well as for MRA (p = 0.142). The results of
this study suggest that MRA is a good alternative to DSA in the preoperative planning of free fibula flap
transplantation.
A successful transplantation of tissue is not only dependent on the good vascular supply of the flap, but
also on the condition of the vessels at the recipient site. As presented in chapter eight anatomic
variations, atherosclerosis and irradiation damage to the acceptor vessels can result in a challenging
and troublesome microsurgical procedure. The possibility to preoperatively assess the presence of
atherosclerosis or irradiation damage to the vessels is studied at the example of the internal mammary
artery that is used as recipient vessel during free flap breast reconstructions. Pre-operative angiography
findings were compared to the degree of vascular damage found during the operation, the clinical
course of the reconstruction and the histology of segments of the recipient artery. A total of 34 patients
were included with the intention of free flap breast reconstruction after radiation therapy. In total 40 free
flaps were transplanted for breast reconstruction. Twenty-one internal mammary arteries had been
within the field of irradiation and 19 out of field. In only two out of six patients with aberrant
angiographies the internal mammary artery had been within the field of radiation. Based on this study
the conclusion had to be drawn, that the damage to the internal mammary vessels cannot always be
detected pre-operatively by angiography, nor by intraoperative examination.
General Discussion
As stated before, in flaps with a variable vascular anatomy or with a suboptimal vascular state, for
example due to atherosclerosis, it is important to be informed about course and quality of the vessels
before the flap elevation starts. Not only the flap pedicle needs to be in good shape to prevent serious
complications after transfer, but also the vessels at the recipient site need to be of good quality, while
the remaining vessels at the donor site need to be able to supply the donor site after the harvest of the
flap. This thesis aimed to shed light on preoperative vascular mapping in different type of
reconstructions and to investigate which method is the most valuable for which type of reconstructions.
All vascular mapping methods have their own advantages and disadvantages.(4-6)
The ankle-arm index (AAI), is a blood pressure index, in which the left arm pressure ought to be used as
denominator and the mean of pressures of both tibial arteries of each leg ought to be used for the
numerator of the AAI for that leg. The advantages are its non-invasiveness, small size, low costs,
portability and the ease to perform the examination. But the disadvantages are its insensitivity to detect
moderate or mild stenosis and it’s lack on information on the vascular state of a single crural vessel.
The advantages of the hand-held Doppler (HDD) are comparable to the AAI: its non-invasiveness, small
size, low costs, portability and the ease to perform the examination. In addition, there are special
sterilized probes available for intra-operative use. The main disadvantage of the most widely used
Doppler probe (8 MHz) is, that it only detects vessels to a depth of 20 mm. Besides, one can never
know for sure what vessel is producing the Doppler signal picked up by the HHD. Furthermore, this
technique does not create a three-dimensional (3D) image of the vasculature and its surrounding
anatomy than can be stored and retrieved later.
118
Similar to HHD, Color Duplex Sonography (CDS) is non-invasive. An advantage compared with the
HHD is its ability to offer more information about anatomy of the vessel and its perforators in reference
to its surrounding tissues, and it can quantitatively analyze which perforator is the dominant one. The
disadvantage of CDS however, is the fact that only skilled personnel, who also have knowledge of free-
flap anatomy, can perform the investigation. In addition, it is less reproducible because of its real-life
dynamics. Another disadvantage in comparison to CTA, MRA and DSA is that CDS - just as HHD -
does not reproduce a 2D or 3D image of the complete vascular anatomy, which can be used by the
surgeon during flap design or flap elevation
The reported advantages of Digital Subtraction Angiography (DSA) include the facts that it gives a 2D
image of the intraluminal vascular anatomy and information about atherosclerotic changes. A
disadvantage of DSA is that it is a time-consuming, invasive technique necessitating the use of iodinate-
contrast medium, which may cause vascular or renal damage as well as allergic reactions. In addition,
there is a radiation dose to be considered. The vasoconstricting effect of the contrast medium, make
exact measurement of the vascular diameter and the assessment of small-caliber vessels unreliable.
Furthermore, the patient has to stay in supine position after the angiography for several hours, to allow
the puncture site to seal. This makes hospital admission often mandatory and therefor makes this
imaging modality relatively expensive. Finally, there is a risk for the development of false aneurysms at
the puncture site.
The advantage Computed Tomographic Angiography (CTA) offers is that it provides an image with
accurate visual details on the intraluminal calibre and course of the vessels and their relationships with
other anatomic structures in a 3D image. This allows surgeons to develop a dissection strategy and opt
for a certain perforator prior to surgery, making the actual dissection safer and swifter. The
disadvantages of CTA are its radiation dose, which is reported to be 5.6 mSv, and the necessity to use
iodinated contrast medium with its previously listed disadvantages. Especially, the vasospastic action is
a serious drawback, because it can make the accurate assessment of small-calibre vessels difficult.
The big advantage of Magnetic Resonance Angiography (MRA) are that it works with magnetism
instead of radiation and. Depending on the software used, it can be used without a non-iodine contrast
medium, making it a relatively safe procedure for the patient. MRA produces a 3D image, which allows
surgeons to accurately assess the course and diameter of the vessels and their relation to other
surrounding structures. The reported disadvantages of MRA are its relatively high costs. Besides, it
cannot be used in claustrophobic patients or a patient with implants containing ferrous metals because
of the scatter artefacts influencing the image quality.
Apart from the descriptive studies in this thesis (chapter two, three, four and five) we investigated the
AAI, HHD, DSA and MRA in comparative studies (chapter six, seven and eight). We concluded that a
combined ankle-arm index and pencil Doppler examination is not accurate enough to detect arteries
with subclinical peripheral arterial occlusive disease or vascular variation and, hence, gives insufficient
information to develop the surgical plan for a free flap of the lower leg. Furthermore, using the example
of the free fibula flap, we drew the conclusion that MRA is a good alternative to DSA in the preoperative
planning of free flap transplantation of the lower leg. Also this thesis showed (in case of the internal
mammary vessels) that DSA is not sensitive and specific enough to detect the irradiation-induced
damage of vessels.
119
In the most recent literature there is a clear tendency towards MRA being used more over and replacing
techniques such as DSA and CTA. (7-9) In the planning of free fibula flaps, MRA is able (in
concordance to our own results) to detect hypoplastic vessels, stenoses, occlusions, or atherosclerotic
changes of the vessels, and enables both accurate assessment of the quality of the main vessels and
their septo- or musculoccutaneous perforators.(7,10-15) CTA is suggested to be a good imaging
modality for the lower leg arteries as well.(16-18) In perforator flaps the use of both MRA (8,9) and CTA
(19-24) is being described. The advantage of CTA is that it is able to detect vessels with a smaller
diameter (<0.5mm).(25) Compared to CTA the advantages of MRA are, as stated earlier, that it is
performed without radiation and there is no need for iodinate contrast medium, which makes it less
harmful for patients.(8-26) It should however be noted that prospective controlled comparative studies
about the use of MRA and CTA in the planning of free fibula flaps are lacking.
Combining the outcome of our studies and the literature we conclude that MRA and CTA are currently
the best methods available to map the vasculature of crural vessels and perforator flaps in general. (4)
In the planning of thin pedicled flaps that are planned close to a defect, in flaps with a more
straightforward anatomy and for intra-operative use, the HHD remains to be mapping method of
choice.(4) DSA is slowly fading out and CDS can be used as an alternative, whenever there are contra-
indications to the use of the other methods of investigation.
When evaluating the outcome of a study, especially a comparative study, it is of importance to look at
the methods used. The strong points of our studies are the prospective and comparative study design.
The investigated technique was compared to the gold standard at that moment. There are however also
limitations, especially with regard to the news value of some of this work in 2013. The field of vascular
mapping is developing so rapidly, that during the design, execution, analysis and report process new
developments make some of this work at present already a bit outdated. When we performed our study
the 1.5 Tesla 3D TOF-MRA technique was the currently used method to depict crural vessels. But from
that time MRA-techniques developed very rapidly.(27-30)
In clinically used scanners the magnetic field increased from 1.5 to 3.0 Teslas in strength. For research
purposes already 7.0 Tesla scanners are used. By the use of higher Tesla scanner it is possible to
improve the signal to noise ratio and the spatial and temporal resolution. As we used a 1.5 Tesla
scanner it is obvious, that with the use of a 3.0 Tesla scanner the resolution of the depicted vessels
could have been improved. At present time, the most clinics still use a 1,5 T MRI scanner and therefore
the outcome of this study however would probably be the same.
Parallel to the improvement of the scanners, new scan techniques have beeing developed, to depict
vessels more accurately, than with the TOF-MRA technique we used. With MRA it is possible to depict
vessels by two different techniques, the flow-dependent angiography (FDA) and flow-independent
angiography (FIA).
The FDA MRA-technique can be divided into Time-of-Flight (TOF) and Phase-Contrast (PC). In TOF-
MRA flowing blood gives a much higher signal than stationary tissue, but areas with slow flow or flow
that is in plane of the image may not be well visualized. With PC-MRA slow flow can be detected much
better and the velocity of moving blood can be detected as well. The disadvantage of PC-MRA is that
the flow can only acquire flow in one direction at a time. To give a complete image of flow, 3 separate
120
image acquisitions in all three directions must be computed. Despite the slowness of this method, the
strength of the technique is that in addition to imaging the flowing blood, quantitative measurements of
blood flow occur at the same time.
In general, slow blood flow is a major challenge in FDA-MRA, because the differences between the
blood signal and the static tissue signal are small. To increase blood signal, which is especially
important for very small vessels or slow flow, contrast agents may be used. Therefore Contrast-
Enhanced (CE) FIA-MRA has been developed. The use of contrast agent is currently the most common
method of acquiring MRA. The contrast medium is injected into a vein, and images are acquired during
the first pass of the agent through the arteries. If the timing of the scanning is correct, the images are
usually of a very high quality. But if the timing is bad or “blood-pool agents” are used the depiction of the
arteries is disturbed by venous overprojection.
Since the injection of contrast agents may be dangerous for patients with renal failure, non-contrast-
enhanced techniques have been developed. These methods are based on the differences of T1, T2 and
chemical shift of the different tissues of the voxel.
The acquisition of the images is changing as well from 3D, which we used, to 4D.(31) Three
dimensional data acquisition is helpful when dealing with complex vessel geometries where blood is
flowing in all spatial directions. The big advantage of the new 4D technique is that the arterial and
venous phases can be divided. In order to overcome the venous overlay and to gain dynamic flow
information the most recent development was the Triple-TWIST MRA (Time-resolved angiography With
Interleaved Stochastic Trajectories), which seems to become the new standard as imaging investigation
in patients suffering from peripheral arterial occlusive disease.(31) With this technique multiple fast
series are obtained of the same area during contrast injection. The maximum intensity image of each
series is selected. All these images together form a dynamic MRI angiography series with high
resolution, without the venous over projection.
Furthermore development of new software packages made it possible to not only asses vascular
imaging via the hospital network, but also for authorized external users. (e.g. Siemens IHE Integrating
Healthcare Enterprise – XDS-1b). This increase in accessibility of the imaging data facilitates expert
consults all over the world and preoperative surgical planning from outside the hospital.
With these improvement in technique we expect that, preoperative mapping in free flap surgery and
especially the role of MRA will get an even more dominant role and will enable surgeons to analyse
more key-aspect of the surgery prior to the surgery itself in the future.(32) Therefore, we expect that the
role of a radiologist familiar with free flap surgery will become more prominent in a reconstructive team
and will create a new dynamic within the team. To combine the necessary knowledge of the different
specialists, we believe that a reconstruction should be discussed and performed in a multidisciplinary
team. Depending on the location of an existing or expected defect, the team should consist of an
oncologist, the ablative surgeon (general surgeon, ENT surgeon, maxillofacial surgeon, orthopaedic
surgeon, gynaecologist, or neurosurgeon), a radiologist, the reconstructive plastic surgeon and an
anaesthesiologist.
A good example of how pre-operative planning is evolving is the Rohner technique for mandible or
maxilla reconstruction, in which the bone segment of a fibula or iliac crest flaps are planned prior to
surgery to fit a defect.(33-37) A CTA is made during the workup that not only allows for vascular
121
imaging, but also generates data that enables the 3D reconstruction of the bony component. The
reconstruction is then further optimized, by creating pre-manufactured cutting guides, reducing the
constraints of sometimes unpredictable intraoperative environments, and maximizing bony contact. With
these techniques the implants that are required for dental bridges can even be placed prior to the bone
transfer, creating a reconstruction, which can immediately bare weight post-surgery. (33) This CAD-
CAM (computer-aided design and manufacturing) technology and the use of stereolithographic models
can improve the accuracy of the surgical result and the intraoperative efficiency.(34,36-38) These
techniques seem to offer improved patient outcome and the reduction of complication and non-union
rates due to this CAD-CAM approach. But there are no comparative studies to investigate the long-term
results in a larger patient group, concerning patient outcome and the reduction of complication and non-
union rates due to this CAD-CAM approach.
Suggestions on future research
Based on our finding during this research, we have several suggestions for future research in the field of
free flap surgery.
1) We showed that the Ankle-Arm Index is insufficient in the preoperative work-up for a free fibula
flap, but we believe that MRA is a good alternative to DSA in the pre-operative work-up of free
fibula flap transfers for reasons stated before. Although the sensitivity found in our study for the
MRA should have ideally been higher, we believe that with current developments with regards
to MRA this is only a matter of time. Although DSA is still advocated as the golden standard for
the detection of peripheral arterial occlusive disease in recent literature,(28) we do believe, that
this technique is becoming more and more obsolete.
To prove that CTA and MRA are just as or even more accurate than DSA in the detection of
peripheral arterial occlusive disease, a comparative study should be conducted, using the
newest scanners and scanning protocols. To investigate the resolution power and the accuracy
of these imaging modalities in the detection of vascular stenosis precisely a comparison to an
anatomical dissection is desirable. It is obvious that this can only be performed in an animal
study.
2) With regards to the preoperative mapping of the recipient vessels, DSA did not prove to be
reliable. We however believe that there are selected cases in which preoperative mapping of
the recipient vessels is necessary, for example after previous surgery or irradiation. In these
cases CTA, MRA or colour duplex could be of additional value, depending on the size and
location of the vessels. Future research can focus on the indication for and the necessity of
preoperative imaging and which method should be used.
3) As discussed above, new developments in the pre-operative planning is virtual surgery in which
key-points of the surgery can already be performed in a virtual setting. Thereby the surgery can
become more straightforward and safer and the results can be optimized. Until now CTA has
been predominantly used for these purposes. We believe however, that if MRA can be used for
these purposes this would further add to patient safety. But due to scattering with metal
implants MRI might not be the most suitable imaging method.
122
References
1 Esser JFS. Artery flaps, Antwerpen, 1929
2 Manchot C. Die Hautarterien des menschlichen Körpers, Leipzig, 1889
3 Sinna R, Boloorchi A, Mahajan AL. What should define a "perforator flap"? Plast Reconstr Surg.
2010 Dec;126(6):2258-63.
4 Smit JM, Klein S, Werker PMN. An overview of methods for vascular mapping in the planning of free
flaps. J Plast Reconstr Aesthet Surg 2010; 63: e674-682
5 Klein S, Hage JJ, van der Horst CMAM. Ankle-arm index versus angiography for the preassessment
of the fibula free flap. Plast Reconstr Surg 2003; 111: 735-743
6 Klein S, Hage JJ. General review: Measurement, calculation, and normal range of the ankle-arm
index: a bibliometric analysis and recommendation for standardization. Ann Vasc Surg 2006; 20:
282-292
7 Miller ME, Moriarty JM, Blackwell KE. Preoperative magnetic resonance angiography detection of
septocutaneous perforators in fibula free flap transfer. Arch Facial Plast Surg. 2011 Jan-
Feb;13(1):36-40
8 Masia J, Clavero JA, Larrañaga JR. Multidetector-row computed tomography in the planning of
abdominal perforator flaps. J Plast Reconstr Aesthet Surg. 2006;59:594-9.
9 Newman TM, Vasile J, Levine JL. Perforator flap magnetic resonance angiography for reconstructive
breast surgery: a review of 25 deep inferior epigastric and gluteal perforator artery flap patients. J
Magn Reson Imaging. 2010 May;31(5):1176-84.
10 Hölzle F, Rstow O, Rau,A, Mücke T. Evaluation of the vessels of the lower leg before microsurgical
fibular transfer. Part II: Magnetic resonance angiography for standard preoperative assessment. Br J
Oral Maxillofac Surg 2010; doi:10.1016/j.bjoms.2010.05.003
11 Fukaya E, Saloner D, Leon P. Magnetic resonance angiography to evaluate septocutaneous
perforators in free fibula flap transfer. J Plast Reconstr Aesthet Surg. 2010 Jul;63(7):1099-104
12 Fukaya E, Grossman RF, Saloner D..Magnetic resonance angiography for free fibula flap transfer. J
Reconstr Microsurg. 2007 May;23(4):205-211
13 Hölzle F, Franz EP, von Diepenbroick VH. Evaluation der Unterschenkelarterien vor
mikrochirurgischem Fibulatransfer: MRA vs. DSA. Mund Kiefer GesichtsChir 2003; 7: 246-253
14 Mast BA. Comparison of magnetic resonance angiography and digital subtraction angiography for
visualization of lower extremity arteries. Ann Plast Surg. 2001 Mar;46(3):261-4
15 Sandhu GS, Rezaee RP, Wright K. Time-resolved and bolus-chase MR angiography of the leg:
branching pattern analysis and identification of septocutaneous perforators. AJR Am J Roentgenol.
2010 Oct;195(4):858-64
16 Chan D, Anderson ME, Domatch BL. Imaging Evaluation of Lower Extremity Infrainguinal Disease:
Role of the Noninvasive Vascular Laboratory, Computed Tomography Angiography, and Magnetic
Resonance Angiography Tech Vasc Interv Radiol. 2010 Mar;13(1):11-22.
17 Foley WD, Stonely T. CT angiography of the lower extremities. Radiol Clin North Am. 2010
Mar;48(2):367-96
18 Ribuffo D, Atzeni M, Saba L. Clinical study of peroneal artery perforators with computed tomographic
angiography: implications for fibular flap harvest. Surg Radiol Anat. 2010 Apr;32(4):329-34.
123
19 Keys KA, Louie O, Said HK, Neligan PC, Mathes DW. Clinical utility of CT angiography in DIEP
breast reconstruction. J Plast Reconstr Aesthet Surg. 2012 Oct 18. pii: S1748-6815(12)
20 Rozen WM, Anavekar NS, Ashton MW. Does the preoperative imaging of perforators with CT
angiography improve operative outcomes in breast reconstruction? Microsurgery. 2008;28(7):516-
23.
21 Molina AR, Jones ME, Hazari A,. Correlating the deep inferior epigastric artery branching pattern
with type of abdominal free flap performed in a series of 145 breast reconstruction patients. Ann R
Coll Surg Engl. 2012 Oct;94(7):493-5.
22 Chiu WK, Lin WC, Chen SY. Computed tomography angiography imaging for the chimeric
anterolateral thigh flap in reconstruction of full thickness buccal defect. ANZ J Surg. 2011
Mar;81(3):142-7
23 Kim EK, Kang BS, Hong JP. The distribution of the perforators in the anterolateral thigh and the
utility of multidetector row computed tomography angiography in preoperative planning. Ann Plast
Surg. 2010 Aug;65(2):155-60
24 Chen SY, Lin WC, Deng SC. Assessment of the perforators of anterolateral thigh flaps using 64-
section multidetector computed tomographic angiography in head and neck cancer reconstruction.
Eur J Surg Oncol. 2010 Oct;36(10):1004-11
25 Rozen WM, Whitaker IS, Stella DL. The radiation exposure of Computed Tomographic Angiography
(CTA) in DIEP flap planning: low dose but high impact. J Plast Reconstr Aesthet Surg.
2009;62:e654-5.
26 Rozen WM, Stella DL, Bowden J. Advances in the pre-operative planning of deep inferior epigastric
artery perforator flaps: magnetic resonance angiography. Microsurgery. 2009;29:119-23.
27 Kramer JH, Grist TM. Peripheral MR Angiography. Magn Reson Imaging Clin N Am. 2012
Nov;20(4):761-76.
28 Fischer A, Maderwald S, Orzada S. Nonenhanced Magnetic Resonance Angiography of the Lower
Extremity Vessels at 7 Tesla: Initial Experience. Invest Radiol. 2013 Mar 13
29 Wheaton AJ, Miyazaki M. Non-contrast enhanced MR angiography: physical principles. J Magn
Reson Imaging. 2012 Aug;36(2):286-304.
30 Nielsen YW, Thomsen HS. Contrast-enhanced peripheral MRA: technique and contrast agents. Acta
Radiol. 2012 Sep 1;53(7):769-77
31 Kinner S, Quick HH, Maderwald S. Triple-TWIST MRA: high spatial and temporal resolution MR
angiography of the entire peripheral vascular system using a time-resolved 4D MRA technique. Eur
Radiol. 2013 Jan;23(1):298-306
32 Saba L, Atzeni M, Rozen WM. Non-invasive vascular imaging in perforator flap surgery. Acta Radiol.
2013 Feb 1;54(1):89-98.
33 Schepers RH, Raghoebar GM, Lahoda LU. Full 3D digital planning of implant supported bridges in
secondarily mandibular reconstruction with prefabricated fibula free flaps. Head Neck Oncol. 2012
Sep 9;4(2):44.
34 Haddock NT, Monaco C, Weimer KA. Increasing bony contact and overlap with computer-designed
offset cuts in free fibula mandible reconstruction. J Craniofac Surg. 2012 Nov;23(6):1592-5.
35 Zheng GS, Su YX, Liao GQ. Mandible reconstruction assisted by preoperative virtual surgical
simulation. Oral Surg Oral Med Oral Pathol Oral Radiol. 2012 May;113(5):604-11.
124
36 Foley BD, Thayer WP, Honeybrook A. Mandibular reconstruction using computer-aided design and
computer-aided manufacturing: an analysis of surgical results. J Oral Maxillofac Surg. 2013
Feb;71(2):e111-9.
37 Rohner D, Guijarro-Martínez R, Bucher P. Importance of patient-specific intraoperative guides in
complex maxillofacial reconstruction. J Craniomaxillofac Surg. 2012 Dec 7.pii:S1010-5182(12)
38 Laible M, Schoenberg SO, Weckbach S. Whole-body MRI and MRA for evaluation of the prevalence
of atherosclerosis in a cohort of subjectively healthy individuals. Insights Imaging. 2012 3: 485-493.